- Title
- An Unusual Phase Transition Driven by Vibrational Entropy Changes in a Hybrid Organic-Inorganic Perovskite
- Creator
- Wei, Wenjuan; Li, Wei; Butler, Keith T.; Feng, Guoqiang; Howard, Christopher J.; Carpenter, Michael A.; Lu, Peixiang; Walsh, Aron; Cheetham, Anthony K.
- Relation
- Angewandte Chemie - International Edition Vol. 57, Issue 29, p. 8932-8936
- Publisher Link
- http://dx.doi.org/10.1002/anie.201803176
- Publisher
- Wiley-Blackwell
- Resource Type
- journal article
- Date
- 2018
- Description
- The driving forces for the phase transitions of ABX3 hybrid organic–inorganic perovskites have been limited to the octahedral tilting, order–disorder, and displacement. Now, a complex structural phase transition has been explored in a HOIP, [CH3NH3][Mn(N3)3], based on structural characterizations and ab initio lattice dynamics calculations. This unusual first-order phase transition between two ordered phases at about 265 K is primarily driven by changes in the collective atomic vibrations of the whole lattice, along with concurrent molecular displacements and an unusual octahedral tilting. A significant entropy difference (4.35 J K−1 mol−1) is observed between the low- and high-temperature structures induced by such atomic vibrations, which plays a main role in driving the transition. This finding offers an alternative pathway for designing new ferroic phase transitions and related physical properties in HOIPs and other hybrid crystals.
- Subject
- ab initio lattice dynamics calculations; hybrid organic-inorganic perovskites; phase transitions; vibrational entropy
- Identifier
- http://hdl.handle.net/1959.13/1448357
- Identifier
- uon:43387
- Identifier
- ISSN:1433-7851
- Language
- eng
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